Attentional Bias Modification Training for Itch: A Proof-of-Principle Study in Healthy Individuals

Abstract

Itch draws our attention to allow imposing action against bodily harm (e.g., remove insects). At the same time, itch is found to interfere with ongoing tasks and daily life goals. Despite the key role of attention in itch processing, interventions that train individuals to automatically disengage attention from itch cues are lacking. The present proof-of-principle attention bias modification (ABM) training study was aimed at investigating whether attention to itch as well as sensitivity to mild itch can be changed. Healthy volunteers were randomized over three ABM-training conditions. Training was done via a modified pictorial dot-probe task. In particular, participants were trained to look away from itch stimuli (n = 38), toward itch stimuli (n = 40) or not trained toward or away from itch at all (sham training, n = 38). The effects of the ABM-training were tested primarily on attention to itch pictures. Secondarily, it was investigated whether training effects generalized to alterations in attention to itch words and mechanical itch sensitivity. The ABM-training did not alter attention toward the itch pictures, and there was no moderation by baseline levels of attention bias for itch. Also, attention bias to the itch words and itch sensitivity were not affected by the ABM-training. This study was a first step toward trainings to change attention toward itch. Further research is warranted to optimize ABM-training methodology, for example increasing motivation of participants. Eventually, an optimized training could be used in patient populations who suffer most from distraction by their symptoms of itch.Clinical Trial Registration: Identifier: NL6134 (NTR6273). The website URL is: https://www.trialregister.nl/

Subliminal attentional bias modification training for itch

“…This study investigated whether attention could be either trained towards visual itch stimuli or away from these stimuli. Results of this study could, however, not support the effectiveness of an ABM-training, neither by affecting attention directly, nor by influencing individuals’ sensitivity to a light cutaneous itch stimulus on the skin ( 16 ).…”

“…The study sample consisted of 117 healthy individuals. This sample size was calculated in line with an earlier study with a comparable design ( 16 ). Participants were included if aged between 18 and 35 years, fluent in either Dutch or English, and with normal vision (corrected with contact lenses if needed).…”

“…In line with an earlier study for itch ( 16 ), participants were distributed across three groups: one trained towards itch (towards-group), one trained away from itch (away-group) and one control-group (sham training). For each participant, the picture pairs were randomly distributed to the pre-training, training and post-training block.…”

“…Descriptive statistics are given as mean ( M ) and standard deviation ( SD ) if not stated otherwise. Reliability of the dot-probe pre- and post-training was calculated with the package “splithalfr” ( 38 ) in line with earlier studies ( 13 , 16 ).…”

“…These kind of trainings use itch-related stimuli, like words or pictures to manipulate individuals’ attention away from (or towards) these stimuli. As yet, only one study employed an ABM-training for itch in healthy individuals which investigated conscious processing of itch-related visual stimuli ( 16 ). This study investigated whether attention could be either trained towards visual itch stimuli or away from these stimuli.…”